TABLE 2.

Pattern of sperm aster formation, timing of first cleavage, and proportions of embryo stages after ICSI with different combinations of sperm heads and centrosome/midpieces.^*

	Sperm aster at 5 hpa (% of fertilized oocytes)				After 3 days of IVC (% of fertilized oocytes)		After 7 days of IVC (% of fertilized oocytes)
Combination†	Large	Short	Absent	Time of first cleavage (hpa)	2–8 Cells	>8 Cells	<8 Cells	8–16 Cells	Morulae	Blastocysts
Th + Tc	0a,A	79.6 ± 3.5a,C	20.4 ± 3.5a,B	29.5 ± 0.9a	54.6 ± 4.6a	45.4 ± 4.6a	28.1 ± 4.1a	57.1 ± 3.0a	8.0 ± 5.5a	6.8 ± 2.1a
Th + Ec	71.7 ± 1.7b,A	28.3 ± 1.7b,B	0b,C	24.4 ± 1.3b	22.2 ± 6.4b	77.8 ± 6.4b	26.7 ± 2.8a	31.6 ± 3.5b	19.7 ± 3.0b	22.0 ± 5.3b
Eh + Ec	71.6 ± 5.9b,A	28.4 ± 5.9b,B	0b,C	24.3 ± 1.2b	23.2 ± 4.8b	76.8 ± 4.8b	20.3 ± 4.4a	33.6 ± 5.2b	23.0 ± 2.0b	23.1 ± 4.7b
Eh + Tc	0a,A	78.6 ± 2.4a,C	21.4 ± 2.4a,B	29.2 ± 1.1a	56.8 ± 6.6a	43.2 ± 6.7a	27.9 ± 4.5a	52.7 ± 5.4a	8.6 ± 4.5a	10.8 ± 4.0a

^*Values are expressed as means ± SD; hpa, hours postactivation; IVC, in vitro culture.

^†Sperm heads: Th, testicular; Eh, ejaculated; centrosome/midpieces: Tc, testicular; Ec, ejaculated.

^a,bWithin the same column, values with different lowercase superscripts differ significantly (P < 0.05).

^A–CWithin the same row, sperm aster configurations with different uppercase superscripts differ significantly (P < 0.05).